In the modern society, demands for optical fiber communication network transmission capacity increase sharply, and there are more and more multiplexing channels of wavelength division multiplexing systems, which needs a great number of lasers having different wavelengths used as light sources of the communication systems. If discrete devices are employed to constitute the communication network, the wavelength division multiplexing systems will be very complicated and bulky, and the maintenance cost will synchronously rise with the transmission capacity. Meanwhile, energy consumption of the communication systems will rise to a surprising degree. To solve the problems of increasingly serious system complexity and energy consumption surge, the best method is to construct the wavelength division multiplexing communication systems by replacing the discrete devices with four-channel integrated chips. Fabricated using monolithic integration technologies, a plurality of devices are integrated into one chip, which may significantly reduce the packaging cost. In addition, integrated optical devices have smaller optical and electrical connection loss and have advantages in optical and electrical properties, stability and reliability.
The integrated semiconductor laser array chip is the most common type of the existing photonic integrated chip. The technology of development of the integrated semiconductor chip is a hot spot at present, and the corresponding packaging technology thereof has drawn more and more attentions. Packaging of this chip is much more complicated than that of the existing conventional discrete cell chip because only careful consideration is take into in terms of optical, thermal, electrical and mechanical structures according to the practical application can good properties of the device be implemented.